I'm sorry to hear this. I too had my 6 year old beagle diagnosed with an aggressive lymphoma last summer so I do know what your going through. One day Bailey just didn't get out of bed in the morning. I looked him over that night and discovered a lump that I did not notice the days prior. Tests came back positive and the vet told me Bailey had but 4-6 weeks to live and would most likely be in serious pain in days.
You may not appreciate this since you're obviously going in a different direction. My thought was it would be selfish of me to put him through whatever an aggressive treatment program would bring him without guarantees and decided to put him down days later before he suffered much. Undoubtedly the hardest thing I've ever done in my life. First dog I ever had, first and LAST time I will ever be present while a pet that close to me is euthanized.
